Abstract: A television signal noise reduction system employs a movement detector for automatically selecting one of three parallel processing paths, the first of which passes the video signal without modification and the other two of which calculate different weighted averages of the current pixel and surrounding pixels from the current frame and the previous frame.

Abstract: A motion detector system reduces visible noise in television image signals by use of a numerical time filter. A sample memory is coupled to the output of the time filter. In the time filter, the sample of the images to be treated is combined with a corresponding and preceding sample delivered by the sample memory. A decision circuit determines whether the combination signal has a parameter of the time filter. A subtraction circuit has a first input coupled to receive the image sample which is to be treated and a second input coupled to receive the corresponding sample delivered by the sample memory. A low-pass filter has parallel inputs for receiving samples delivered by the subtracting circuit. A sign output is derived from an exclusive OR circuit coupled to a low-pass filter and a band-pass filter.